In endoscopic surgery, also known as laparoscopic surgery, the surgeon makes a plurality of incisions in the abdominal region or the like of the patient, places respective trocars or tubular instruments in the incisions, and inserts a laparoscope (camera) and a plurality of pairs of forceps through the trocars into the body cavity to access the target region. Grippers for gripping a biological tissue or the like, scissors, electrosurgical scalpel blades, or the like are mounted as end effectors on the distal end portions of the forceps.
After having inserted the laparoscope and the forceps into the body cavity, the surgeon performs a surgical operation on the target region with the forceps while watching an image of the target region in the body cavity that is captured by the laparoscope and displayed on a display monitor which is connected to the laparoscope. Since the laparoscopic surgery does not require a laparotomy, it is less burdensome on the patient and greatly reduces the number of days required for the patient to spend in the hospital before recovering from the operation or being released from the hospital. The laparoscopic surgery is expected to increase a range of surgical operations to which it is applicable.
Forceps that are to be inserted through trocars include general forceps having no articulated joints on distal end portions thereof. Efforts are being made to develop another type of forceps that is categorized as a so-called medical manipulator having articulated joints on its distal end which make it possible for an end effector thereon to roll and tilt (see Japanese Patent No. 4391762, for example). Such a medical manipulator allows the end effector to move with greater freedom in body cavities, lets the surgeon practice surgical techniques easily, and is applicable to a wider range of surgical operations.